I know I won’t go all the way (full stack) , so do I really need to take the data visualization course ?
Remember, the Data Visualisation section in freeCodeCamp only covers frontend concepts/tools.
If you want to be a frontend developer, then it might be useful. If you want to be a backend developer, then it probably will not.
The backend section of the content only begins at the APIs and Microservices section.
Hope this clarifies